Composition of matter



Patented May 15, 1923.

PATENT OFFICE.

NELS L. OLSON, F DETROIT, MICHIGAN.

COMPOSITION OF MATTER.

No Drawing.

To all whom it may concern:

Be it known that I, New L. OLsoN, a citizen of the United States of America, residing at Detroit, in the county of \Vayne and State of Michigan, have invented certain new and useful Improvements in Composition of Matter, of which the following is a specification.

This invention relates to a composition of matter particularly adapted for use in the heat treatment of iron and steel articles, in any of the various processes in which the carbon content of the surface of the articles treated is to be modified.

Boxes or other containers for use in carbonizing have hitherto been made of iron and steel compositions containing varying amounts of carbon and it has been found that when such boxes are new a certain varying proportion of the carbonizing ma terial is taken up by the boxes or containers instead of by the articles placed therein for treatment so that there is av lack of uniformity in the product which in many cases re sults in considerable loss. After such containers have been used for several treatments the material of which the container is made will have taken up substantially all of the carbon capable of combining therewith at the temperatures used in the carbonizing treatment and thereafter the results obtained in the finished product will be substantially uniform.

The primary object of the present invention is to provide an alloy containing iron together with suflicient quantity of carbon to prevent any substantial quantity of carbon being taken up from the carbonizing material used in the container, the alloy containing in addition other elements rendaring it highly resistant to heat and oxidation and elements improving other physical qualities of the alloy.

It has hitherto been proposed to use for such carbonizing boxes an alloy containing chromium and nickel with iron, but so far as I am aware, carbon has never been used in any such alloys, and therefore the iron in such alloys will take up a certain percentage of the carbon from the carbonizinp' material, especially during the first use of such Application filed June 17, 1922. Serial No. 568,909.

boxes. The alloy I have found best suited for this purpose contains iron from ten per cent. to twenty-five per cent, chromium ten per cent. to twenty per cent, nickel sixty per cent. to seventy per cent, carbon two per cent. to six per cent, silicon one per cent. to three per cent, manganese one per cent. to two per cent, and aluminum one percent. to two per cent. The addition of molybdenum, vanadium, zirconium and tungsten in small percentages as one-half to two per cent, improves the physical quality of the boxes for use in certain conditions and under certain temperatures. 65

As is well known, nickel is itself resistant to heat, and when chromium is added thereto in an alloy the property of resistance to warping is improved and the material is made harder and more resistant to oxida tion. Silicon also increases the resistance to oxidation. The aluminum and manganese improve the grain structure of the alloy and molybdenum and vanadium increase the tensile strength of the alloy. It will be observed that nickel and chromium form the preponderating elements in the alloy though the iron may run as high as twentyfive per cent. The carbon content of this alloy is very high and this increased carbon content forms an essential feature of my invention. The fusion point of the alloy is quite high and consequently comparatively thin walls may be used, thereby lowering the weight and the initial cost of the containers.

1 claim 1. A metallic alloy subjected when in use to external heat at high temperatures composed of iron from ten per cent. to twentyfive per cent. chromium from ten per cent. to twenty per cent, nickel. from sixty per cent. to seventy per cent. carbon from two per cent. to six per cent, silicon from one per cent. to three per cent, aluminum one per cent. to two per cent, and manganese from one per cent. to two per cent.

2. A metallic alloy containing from sixty per cent. to seventy per cent. nickel, ten per cent. to twenty per cent. chromium, one per cent. to three per cent. silicon, two per cent. to six per cent. carbon, one per cent. to two per cent. aluminum, one per cent. to two per il-5mm cent. manganese, one-half per cent. to two chromium, iron and carbon from two per per cent. vanadium, and the remainder iron. cent. to six per cent. 10

A container for use in carbonizing ar- In testimony whereof I affix my signature ticles containing iron consisting of a heat in presence of two Witnesses. 5 resisting box composed of an alloy substan- NELS L. OLSON.

tizilly incapable of combining with carbon Witnesses: at carbonizing temperatures of iron, said LEWIS E. FLANDERS,

box composed of an alloy containing nickel, ARTHUR MiNNICK. 

